Logging electrical load at small grocery store

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Does the refrigeration equipment use electric defrost or hot gas defrost? And could it be retrofitted to hot gas defrost? Big money saver right there. Walmart only uses electric defrost, which I never understood.
 
Take a thermal gun and see if any or all of the holes in and out of the coooler are sealed. Resealing outside and sealing inside both ends, of electrical raceways is a must if not than condesation will build up. Staining or puddles can be a tell. If the chase pipe is rusting then remove it and be sure to coat the outside of the replacement pipe with silicon when reinserted. You can also use an enlarged reducing washer to help seal any rusting holes.

A cheap fix if able would be to blue foam the top of the box or any open sides.
Of course this might get into building code issues of exposed foam in this type of setting.
The R value is only three and it might not be a viable answer anyways.
 
sparkyrick said:
Does the refrigeration equipment use electric defrost or hot gas defrost? And could it be retrofitted to hot gas defrost? Big money saver right there. Walmart only uses electric defrost, which I never understood.
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I definitely have got a lot of good info. here on what to look at and I think I will be able to save them some money. How much, who knows. I will look into if they are using hot gas or electric defrost.
 
sparkyrick said:
Does the refrigeration equipment use electric defrost or hot gas defrost? And could it be retrofitted to hot gas defrost? Big money saver right there. Walmart only uses electric defrost, which I never understood.
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In the three or four chains I work in hot gas is being phased out for electric defrost.

According to the refrigeration contractors that is due to the fact hot gas defrost often results in leaks. The constant expansion and contraction of the copper lines when you switch which line is hot result in wearing of the copper against things.
 
iwire said:
I can see that making great sense on large chillers working at partial loads. :)

The stores I work use many small compressors of different sizes on a central common manifold or header. The control systems use the most efficient combination of compressors to maintain the pressure set point. It is a constantly changing volume of gas they need to pump due to different cases going into cooling mode.

They have tried VFDs but they never seem to work out, I always see them bypassed.
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In the OPs case hot or cool gas defrost over electric defrost might be an option in addition to the waste heat reclaim. Out of curiosity, would you happen to know the price to add a reclaim heat exchanger to an existing sealed system?




FWIW, overseas, secondary loop refrigeration is taking off both because of simplicity and efficiency. Maintaining refrigerant flow rates are just contained to the packaged unit, the condenser and evaporator cooled/heated via a secondary loop/ Water for the condenser and water/propylene glycol for the evaporator to cases loop. If the store ever gets a full make over it might be worth considering.
 
iwire said:
In the three or four chains I work in hot gas is being phased out for electric defrost.

According to the refrigeration contractors that is due to the fact hot gas defrost often results in leaks. The constant expansion and contraction of the copper lines when you switch which line is hot result in wearing of the copper against things.
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Never knew that! Common problem I have heard with hot defrost is maintaining adequate condenser/evaporator temperatures during the winter when the units go into defrost. (think pulling heat from -5) Another thing I have heard is its substantially more complicated. Doesn't it also require a 3rd line going to the cases?
 
mbrooke said:
Never knew that! Common problem I have heard with hot defrost is maintaining adequate condenser/evaporator temperatures during the winter when the units go into defrost. (think pulling heat from -5) Another thing I have heard is its substantially more complicated. Doesn't it also require a 3rd line going to the cases?
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FWIW I was just repeating what other contractors have told me, that may be true or just myth.

The stores that I work in that use reverse gas do not have a third line going to the case but at the refrigeration rack in the mechanical room there is a lot more plumbing, valves and controls.

Also each case needs its own pair of lines from the rack to the case. On the other hand with electric defrost they can run a large set of refrigerant lines out and put control valves at each case.
 
As others post, refrigeration is a large part of the load and is often of poor eficiency.
IME in smaller stores a lot of display fridges and freezers are self contained with the compressor and condenser built in to the cabinet as in a domestic appliance. If this is the case, it is most important to ensure that the appliance is properly ventilated and that the condenser is kept clean. All too often such appliances are tight against a wall when the suppliers recomends say 6 inches clearance, and are never cleaned.

Many suppliers of beer, soft drinks, and ice cream offer free fridges and freezers to display and sell their product, these are often of very poor efficiency even if fairly new. If these appliances are cord and plug connected, then use of a plug in, consumer grade power and energy monitor could prove interesting.

Lighting can waste a lot of energy, many small stores have fixtures in a regular grid pattern that is completly unsuited to the actual store layout. As a result many fixtures only light the top of shelves, racks, cabinets and fridges, and contribute little or nothing to general illumination. Such fixtures can be removed or at least dissconnected.

Finally ensure that lighting is turned off when not needed ! this may seem elementary but a suprising number of shops light toilets, cleaners cupboards or storage rooms 24/7.

If the premises are phyisicly contiguos with other homes or busineses, rather than a being a detached structure, it would be worth checking that no neighbours are consuming your customers power. This does happen both due to deliberate theft, and by mistake, especialy in premises that have been subdivided after being wired.
 
iwire said:
FWIW I was just repeating what other contractors have told me, that may be true or just myth.

The stores that I work in that use reverse gas do not have a third line going to the case but at the refrigeration rack in the mechanical room there is a lot more plumbing, valves and controls.

Also each case needs its own pair of lines from the rack to the case. On the other hand with electric defrost they can run a large set of refrigerant lines out and put control valves at each case.
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Id say true. Its just a guess for me but it makes a lot of sense.
 
mbrooke said:
Id say true. Its just a guess for me but it makes a lot of sense.
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That was my feeling as well.

Figure 2-4 defrost cycles per day and after a few years that could be a lot of wear.

I was just trying to be clear I had not seen it first hand. :)
 
broadgage said:
IME in smaller stores a lot of display fridges and freezers are self contained with the compressor and condenser built in to the cabinet as in a domestic appliance. If this is the case, it is most important to ensure that the appliance is properly ventilated and that the condenser is kept clean. All too often such appliances are tight against a wall when the suppliers recomends say 6 inches clearance, and are never cleaned.
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Most of our work is with remote cooled cases but there are always a few self contained units and they are always full of dirt and crud. No one services them, the chains hire refrigeration contractors to watch the remote cooled cases but not the self contained cases so they run with no service until they break down and get replaced.


Many suppliers of beer, soft drinks, and ice cream offer free fridges and freezers to display and sell their product, these are often of very poor efficiency even if fairly new.
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For sure on that here as well.



Finally ensure that lighting is turned off when not needed ! this may seem elementary but a suprising number of shops light toilets, cleaners cupboards or storage rooms 24/7.
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I see that surprisingly often as well. Even in stores with full lighting control systems they often get bypassed every night because the night crews want full lighting instead of the reduced level.

Not only does that hurt the electric bill it adds to lamp, ballast replacement costs.

Back to the OP, one thing that has not been mentioned is closing in open cases to save energy.

There are companies that make retrofit doors for existing open cases, I am sure they are not cheap but much less costly than replacing the case if it is decent.

Here is one such company http://www.anthonyintl.com/en/Products/CloseTheCase/CloseTheCaseRetrofit.aspx


 
iwire said:
In the three or four chains I work in hot gas is being phased out for electric defrost.

According to the refrigeration contractors that is due to the fact hot gas defrost often results in leaks. The constant expansion and contraction of the copper lines when you switch which line is hot result in wearing of the copper against things.
Click to expand...

Probably why Wally World uses all electric defrost. Thanks for the info.
 
iwire said:
That was my feeling as well.

Figure 2-4 defrost cycles per day and after a few years that could be a lot of wear.

I was just trying to be clear I had not seen it first hand. :)
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Out of curiosity, how is demand type defrost? Ive heard its another major energy saver but Im not sure whats on the market regarding that.
 
What does he have for outdoor lighting and what controls are on those lights? Ineffective controls waste energy plus cause bulbs & ballasts to burn out sooner. Changing controls is quick & cheap.

Disclosure: Our company makes outdoor light controls.
 
broadgage said:
IME in smaller stores a lot of display fridges and freezers are self contained with the compressor and condenser built in to the cabinet as in a domestic appliance. If this is the case, it is most important to ensure that the appliance is properly ventilated and that the condenser is kept clean. All too often such appliances are tight against a wall when the suppliers recomends say 6 inches clearance, and are never cleaned.

Many suppliers of beer, soft drinks, and ice cream offer free fridges and freezers to display and sell their product, these are often of very poor efficiency even if fairly new. If these appliances are cord and plug connected, then use of a plug in, consumer grade power and energy monitor could prove interesting.
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A point I was going to bring up there. Small stores are likely to have more self contained refrigerated units. They are tempting to owners/managers because their upfront expense will be less. Besides the points you mentioned, those units are also dumping their waste heat into the store which is not a problem during heating season but will increase air conditioning load.
 
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